U.S. Pat. No. 3,341,352 to Ehlers relates to a process for treating metallic surfaces with an ion beam for coloring purposes. The metals treated with nitrogen ions are aluminum, copper, titanium, magnesium, and beryllium.
U.S. Pat. No. 4,105,443 to Dearnaley et al relates to the ion implantation of cemented carbides with nitrogen. This is a physical process of implantation not involving any chemical reaction.
U.S. Pat. No. 4,250,009 to Cuomo et al relates to a process of sputtering to deposit a plurality of metals upon a substrate. The composition of the resulting film is varied in accordance with externally applied control inputs. This patent describes an ion source designed for the deposition of thin films.